Opportunistic Relaying for Dual-Hop Wireless MIMO Channels
In wireless relay networks, the use of multiple antennas at both the source and destination can increase the capacity linearly with the number of antennas. In this paper, the authors investigate amplify-and-forward dual-hop MIMO relay networks without channel state information at the relay nodes, i.e., non-coherent case. In contrast to the conventional approach where the available power is equally distributed over all relay nodes, they propose an opportunistic relaying approach in which only a few Very Important Relays (VIR) are selected to share the power. By doing so, the array gain of MIMO relay networks can be enhanced and thus maximize the ergodic capacity.